A survey study on some neurological symptoms and sensations experienced by long term users of mobile phones

A survey study was conducted to investigate the possible effects of mobile phone on headache, dizziness, extreme irritation, shaking in the hands, speaking falteringly, forgetfulness, neuro-psychological discomfort, increase in the carelessness, decrease of the reflex and clicking sound in the ears. There is no effect on dizziness, shaking in hands, speaking falteringly and neuro-psychological discomfort, but some statistical evidences are found that mobile phone may cause headache, extreme irritation, increase in the carelessness, forgetfulness, decrease of the reflex and clicking sound in the ears.

Prevalence of tremor in multiple sclerosis and associated disability in the Olmsted County population

We applied a clinical tremor rating scale and measures of disability to 200 of 201 multiple sclerosis patients from a prevalence cohort in Olmsted County, Minnesota. In a community-based sample, tremor was found clinically in 51 (25%) patients, although only 6 (3%) patients had severe tremor. Within the population as a whole, tremor was strongly associated with impairment disability and handicap.

Clinical characteristics of Parkinson's disease among Inuit in Greenland and inhabitants of the Faroe Islands and Als (Denmark)

In earlier studies, we found high age-adjusted prevalences of Parkinson's disease (PD) in the Faroe Islands (209 per 100,000 inhabitants) and in Greenland (187.5 per 100,000 inhabitants) compared to the age-adjusted prevalence on the island of Als in the southern part of Denmark (98.3 per 100,000 inhabitants). We thoroughly examined patients with suspected parkinsonism using internationally accepted diagnostic criteria. In the present study, we found no significant clinical differences between patients with PD in the three areas, despite this high difference in prevalence. However, comparing the age at examination and age at treatment, the patients were younger in Greenland, a higher proportion of patients had cognitive decline, and they had a higher mean Hoehn and Yahr rating score, although they received a lower levodopa dose. A higher proportion of the patients in Greenland were newly diagnosed than in the other two areas.

Profile of families with parkinsonism-predominant spinocerebellar ataxia type 2 (SCA2)

Spinocerebellar ataxia type 2 (SCA2) has been recognized recently as an uncommon cause of parkinsonism, an alternate presentation to the typical cerebellar disorder. This research review summarizes the existing literature on parkinsonism-predominant presentation SCA2 and presents new clinical cases of patients with this condition. Various phenotypes are noted in this subtype of SCA2, including parkinsonism indistinguishable from idiopathic Parkinson's disease (PD), parkinsonism plus ataxia, motor neuron disease, and postural tremor. In several kindreds with multiple affected family members, the SCA2 expansion segregated with disease; in addition, several single cases of parkinsonism with and without a family history are also described. The number of repeats in symptomatic patients ranged from 33 to 43. Interruption of the CAG repeat with CAA, CGG, or CCG was found in some individuals, possibly stabilizing the repeat structure and accounting for the relative stability of the repeat size across generations in some families; allele length is not necessarily indicative of trinucleotide repeat architecture. Positron emission tomography scanning in one family showed reduced fluorodopa uptake and normal to increased raclopride binding with a rostrocaudal gradient similar to that found in idiopathic PD. This review emphasizes the importance of testing for SCA2 in patients with parkinsonism and a family history of neurodegenerative disorders. Testing for SCA2 is also important in studies of inherited parkinsonism.

Clinicopathological investigation of vascular parkinsonism, including clinical criteria for diagnosis

Vascular parkinsonism (VP) is difficult to diagnose with any degree of clinical certainty. We investigated the importance of macroscopic cerebral infarcts and pathological findings associated with microscopic "small vessel disease" (SVD) in the aetiology of VP. The severity of microscopic SVD pathology (perivascular pallor, gliosis, hyaline thickening, and enlargement of perivascular spaces) and the presence of macroscopically visible infarcts were assessed in 17 patients with parkinsonism and no pathological evidence of either Parkinson's disease or any histopathological condition known to be associated with a parkinsonian syndrome, and compared with age-matched controls. Microscopic SVD pathology was significantly more severe in the parkinsonian brains. Most patients presented with bilateral bradykinesia and rigidity together with a gait disorder characterised predominantly by a shuffling gait. Four patients presented acutely with hemiparesis and then progressed to develop a parkinsonian syndrome. They could be distinguished from the remaining VP patients by the presence at autopsy of macroscopically visible lacunar infarcts in regions where contralateral thalamocortical drive might be reduced. The clinical features at presentation varied according to the speed of onset and the underlying vascular pathological state. New clinical criteria for a diagnosis of VP are proposed based on the clinicopathological findings of this study.

Diabetes mellitus and progression of rigidity and gait disturbance in older persons

BACKGROUND

Parkinsonian-like signs, including rigidity, gait disturbance, and bradykinesia, are common and progressive in old age and are associated with morbidity and mortality. Few risk factors for these signs have been identified. Diabetes mellitus, also a common chronic condition in old age and known to be associated with physical and neurologic disability, may be associated with parkinsonian-like signs.

OBJECTIVE

To examine the relation of diabetes to four parkinsonian-like signs.

METHODS

Participants were 822 older Catholic clergymen and women who were without clinically diagnosed Parkinson disease or dementia at baseline. For up to 9 years, they had uniform annual evaluations, which included a modified version of the motor portion of the Unified Parkinson's Disease Rating Scale, from which previously established measures of four specific parkinsonian-like signs were derived. Participants were evaluated for the presence of diabetes, based on direct medication inspection and history.

RESULTS

Diabetes was present in 128 (15.6%) participants. In random effects models controlling for age, sex, and education, diabetes was associated with worsening rigidity (p < 0.01) and gait (p < 0.05), over an average of 5.6 years of follow-up, but not with change in bradykinesia or tremor. The presence of stroke did not substantially affect the association of diabetes with rigidity but reduced the association of diabetes with gait to a trend (p = 0.08).

CONCLUSION

Diabetes may be a previously unrecognized risk factor for progression of parkinsonian-like signs in older persons.

Differences in age at onset and familial aggregation between clinical types of idiopathic Parkinson's disease

Idiopathic Parkinson's disease (PD) can be subdivided by its patterns of motor symptoms into tremor-dominant (TDT), akinetic-rigid (ART), and mixed type (MT). Our objective was to determine whether age at onset and family history are different in these three types. In total, 366 patients with PD were assigned in a standardized approach to one of the three subtypes. Age at onset and family history were obtained in all patients and all presumably affected family members were examined. Mean ages at disease onset were similar in all three groups, but distribution of age at onset was markedly different: monophasic in TDT with a peak around 60 years, biphasic in ART with two peaks, one in the middle of the sixth decade (earlier onset, ART-EO), another during the first half of the seventh decade (later onset, ART-LO), and increasing with age only in MT patients A positive family history was significantly associated only with TDT (odds ratio = 5.7) and ART-EO (odds ratio = 7.8), but not with MT or ART-LO patients. Segregation analysis suggested an autosomal recessive mode of transmission in ART-EO and an autosomal dominant mode of transmission in TDT.

An overview of parkinsonian syndromes: data from the literature and from an Italian data-base

Recent molecular biology research on neurodegenerative diseases, including parkinsonisms, has identified mutations in the genes that code for the proteins alpha-synuclein and tau, which have been used to classify them into synucleinopathies and tauopathies. The synucleinopathies include, besides the most common and well studied Parkinson's disease (PD), dementia with Lewy bodies, which accounts for approximately 20% of all cases of dementia in the elderly, and multiple system atrophy, whereas the tauopathies include rare and rapidly progressive syndromes, such as progressive supranuclear palsy and corticobasal degeneration. Data we collected at our center in over 2900 parkinsonian patients show that PD accounts for no more than 70% of parkinsonisms. The various syndromes have many features in common that make the differential diagnosis difficult in the early stages of disease. Our data are consistent with the findings reported in the international literature and provide additional information useful for differential diagnosis.

Novelty seeking and harm avoidance in Parkinson's disease: effects of asymmetric dopamine deficiency

OBJECTIVES

Although changes in novelty seeking and harm avoidance have been reported among patients with Parkinson's disease (PD), the findings regarding the neurochemical correlates of such changes are inconsistent. This study was designed to examine the hypothesis that different patterns of motor and neurochemical asymmetry in PD may have contributed to the conflicting results.

METHODS

Forty PD patients (divided into two groups according to initial asymmetry in dopamine deficit: left hemisphere, n = 22; right hemisphere, n = 18) and 17 age matched healthy controls completed the Tridimensional Personality Questionnaire (Cloninger, 1987).

RESULTS

Only patients with greater dopamine loss in the left hemisphere showed reduced novelty seeking, whereas only patients with reduced dopamine in the right hemisphere reported higher harm avoidance than matched healthy controls. Novelty seeking was not associated with disease duration, current motor symptoms, or medication, whereas harm avoidance was significantly correlated only with the severity of bradykinesia and depression.

CONCLUSIONS

Approach and avoidance reflect different patterns of dopaminergic asymmetry. Whereas reduced novelty seeking reflects deficit in the mesolimbic branch of ascending dopamine transmission in the left hemisphere, increased harm avoidance is associated with greater dopamine loss in the right striatum.

A clinical study of non-parkinsonian and non-cerebellar tremor at a specialty movement disorders clinic

BACKGROUND

No Indian studies have focused on the clinical aspects of tremor.

AIMS

To study the distribution of various etiological types of tremor disorders at a Movement Disorders clinic of a large, tertiary care hospital in India and to study the clinical characteristics of essential tremor [ET].

SETTING AND DESIGN

Prospective cross-sectional study at a tertiary care specialty clinic.

MATERIAL AND METHODS

Patients presenting with tremor as the chief complaint, with no features suggestive of parkinsonism, cerebellar disorder or acute central nervous system disorder, were included. Patients were classified into different etiological categories from detailed history. All patients diagnosed as ET, were further interrogated for a detailed family history and examined for characteristics of tremor. These patients were then classified into 'definite', 'probable' and 'possible' ET.

RESULTS

One hundred and six patients (mean age 44.4 + 15.1 years) were examined during the study period. ET (59.4%) and dystonic tremor (21.7%) were the commonest types. Only 43% patients of ET reported progression; response to alcohol was seen in only a single patient, a positive family history was present in 52.4% and in 36.4% the inheritance was of an autosomal dominant pattern.

CONCLUSION

ET and dystonic tremor are the commonest causes of tremor presenting to a specialty Movement Disorders clinic. Most patients with ET have high-frequency tremor, with mild asymmetry in 40% cases. Alcohol responsiveness may not be a useful tool in the diagnosis of ET.

[Hypotonic-hyporesponsive episode (HHE) following vaccination with a combined vaccine against diphtheria, tetanus and pertussis (whole cell vaccine -DTPv)]

The combined vaccine against diphtheria, tetanus and pertussis containing the whole cell component of pertussis (DPTw) is characterized by high effectiveness but is also one of the most reactogenic vaccines. Adverse events following this vaccine includes a hypotonic-hyporesponsive episode, however this episode is not well known to general practitioners and pediatricians, so the data about its incidence are not reliable. The aim of this study was to characterize the clinical features of HHE following DTPw vaccine, to estimate the ability to diagnose this syndrome by GPs and pediatricians and to assess the registration system of HHE in Poland. The studied group consisted of 49 children, patients of the Regional Consultation Polyclinic in Kraków in the years 1997-2002, in whom HHE was diagnosed. The following were analysed: sex and age, interval between vaccination and HHE, relationship to the number of DTPw doses, duration of HHE and, based on the referral, the diagnosis made by a GP. The average age of children at the moment of HHE was 3.4 months, but 46/49 children were under 6 months. The symptoms of HHE occurred after a few minutes to 48 hours after vaccination and in two children similar episodes were observed on the 6th day after vaccination, which is not consistent with the definition of HHE. Most often HHE was observed after the first (21/49) and the second (16/49) dose of DTPw. In two children HHE occurred twice, after two consecutive doses of DTPw. In four cases only GPs referring patients have diagnosed HHE. Thirty children from the studied group were further vaccinated against diphtheria, tetanus and pertussis. 61 doses of DTPa (a vaccine with acellular pertussis component) were used and in no case was the adverse event observed. Based on the results obtained it has been concluded that some difficulties are observed in the diagnosis of HHE made by GPs and pediatricians, therefore the number of HHE cases registered in Poland decreased. Hypotonic-hyporesponsive episode should be taken into consideration in differential diagnosis of the nervous system diseases. Therefore, it is extremely important to ask parents about the history of vaccinations in their children.

Increased risk of head tremor in women with essential tremor: Longitudinal data from the Rochester Epidemiology Project

In one cross-sectional study of a community in northern Manhattan, women with essential tremor (ET) were more likely to have head tremor than were men. In that study, patients were seen at one point in time, rather than followed longitudinally. Head tremor often develops after arm tremor, and its appearance in patients with ET may therefore be a function of duration of follow-up. In a second epidemiological study utilizing the Rochester Epidemiology Project, in which ET subjects were followed from disease diagnosis to death, we determined whether there was an association between female gender and head tremor. We utilized the records-linkage system of the Rochester Epidemiology Project to identify ET cases. Records were reviewed and clinical data abstracted by a neurologist specializing in movement disorders. A second neurologist reviewed a subsample of records. There were 107 ET cases (69 women, 38 men) followed for 10.1 +/- 9.1 years from ET diagnosis to death. Head tremor was present in 37 (53.6%) women and 5 (13.2%) men (odds ratio [OR] = 7.6, 95% confidence interval [CI] = 2.7-21.9, P < 0.001). In a multivariate linear regression analysis, women remained at high risk for head tremor (OR = 6.5, 95% CI = 2.2-19.0, P = 0.001) independent of disease duration. We found in this longitudinal epidemiological study that women with ET were six times more likely to develop head tremor over the course of their illness than were men. The reason for the association between gender and head tremor, which has now been demonstrated in several studies, is not known, but it could reflect gender differences in the distribution of disease pathology within the brain.

A screening instrument for a Sicilian neuroepidemiological survey in the elderly

We evaluated the sensitivity and specificity of a screening instrument developed for use in a two-phase neuroepidemiological survey in Sicily. The Sicilian Epidemiological Dementia Study (SEDES) project will evaluate the prevalence and incidence of dementia, parkinsonisms and essential tremor in four Sicilian municipalities. It is a two-phase door-to-door survey. To identify subjects with possible neurological disorders, in this study, we developed a screening instrument including a symptoms questionnaire and simple physical tasks for parkinsonisms and essential tremor. The Mini-Mental State Examination (MMSE) was chosen for screening dementia. The symptoms questionnaire and simple tasks developed to identify possible patients with parkinsonism and essential tremor, was tested in a hospital setting. To evaluate sensitivity, we selected 20 patients with essential tremor and 40 with Parkinson's disease (20 with Stages I-II and 20 with Stages III-V) [Neurology 17 (1967) 427]. To evaluate specificity we also selected 20 healthy subjects. The screening instrument was administered in a hospital setting by trained interviewers. Sensitivity of the screening instrument (questionnaire plus simple tasks) was 100% for essential tremor and parkinsonisms regardless of the stage. Specificity of the instrument was 90% (95% CI 66.9-98.2); the predictive positive value was 90.9%, while the negative predictive value was 100%. Even if validity was assessed in a hospital setting, the high sensitivity and specificity obtained suggest that the instrument could be an appropriate screening tool for parkinsonisms and essential tremor in a two-phase neuroepidemiological survey.

Risk of action tremor in relatives of tremor-dominant and postural instability gait disorder PD

BACKGROUND

Action tremor may be more prevalent in relatives of patients with Parkinson's disease (PD) than in relatives of control subjects. This tremor could represent mild PD or essential tremor. An estimate of the risk of this condition in families of patients with PD is important when studying the genetics of PD.

OBJECTIVE

S: To determine the risk of action tremor in first-degree relatives of probands with tremor-dominant PD (TD-PD) and postural instability gait disorder PD (PIGD-PD) compared with first-degree relatives of control probands.

METHODS

PD and control probands participated in a familial aggregation study of PD. The presence of action tremor in their relatives was ascertained from reports of one or more informants. Relatives who met diagnostic criteria for PD were excluded. Cox proportional hazards models adjusting for gender, education, race, and vital status (dead vs alive) of the relatives were used to assess the relative risk (RR) of action tremor in first-degree relatives of PD probands vs first-degree relatives of control probands.

RESULTS

There were 487 PD probands, 409 control probands, and 5,563 relatives. The risk of action tremor was higher in the relatives of TD-PD probands than in the relatives of control probands (RR = 2.14; 95% CI = 1.53 to 2.98) but not in the relatives of PIGD-PD probands compared with the relatives of control probands (RR = 1.81; 95% CI = 0.66 to 5.02).

CONCLUSION

The risk of action tremor was increased in the relatives of PD probands, particularly when they had TD-PD. Whether the tremor in these relatives represents essential tremor or an isolated manifestation of PD requires further investigation.

Factors associated with increased risk of head tremor in essential tremor: a community-based study in northern Manhattan

Head tremor is one of the major expressions of essential tremor (ET). It is not well understood why some patients develop head tremor, whereas others do not. A study of the characteristics of patients with head tremor has not been undertaken. Our goal was to estimate the prevalence of head tremor and to identify demographic and clinical characteristics associated with an increased risk of head tremor in ET. Cases were ascertained from a community-based study of ET in northern Manhattan, New York. Arm tremor severity was rated with a total tremor score. Logistic regression analyses resulted in odds ratios (OR). Head tremor was present in 37 (34.9%) of 106 ET cases. Female gender was associated with a fourfold increased risk of head tremor (OR = 3.73; P = 0.005). Total tremor score was divided into quartiles; individuals in the lowest or highest quartile were four times more likely to have head tremor (OR = 4.16; P = 0.001). Individuals with both risk factors (female gender and lowest or highest total tremor score quartile) were 16 times more likely to have head tremor (OR = 15.88; P = 0.0006). Being related to a proband with head tremor marginally increased the risk of head tremor (OR = 11.30; P = 0.08). Age and tremor duration did not influence the risk of head tremor. We identified several factors that were associated with an increased risk of head tremor in ET; female gender, coexisting arm tremor that was either very mild or extremely severe, and relation to an ET case with head tremor. These disease associations require further exploration, and might provide insight into the mechanisms underlying head tremor.

Rest tremor in patients with essential tremor: prevalence, clinical correlates, and electrophysiologic characteristics

BACKGROUND

Isolated rest tremor, which is observed in some patients with essential tremor (ET), poses a diagnostic challenge. The phenomenon has been examined in few studies and is poorly understood.

OBJECTIVES

To determine the prevalence and study the clinical correlates of rest tremor in ET and to examine the electrophysiologic features in a subgroup of patients.

METHODS

Sixty-four patients with ET cared for at a tertiary referral center underwent neurologic examination. Five of 12 patients with rest tremor also underwent quantitative computerized tremor analysis using accelerometry and handwritten spiral analysis.

RESULTS

Twelve of 64 patients with ET had rest tremor (prevalence, 18.8%; 95% confidence interval, 9.2%-28.4%). Compared with the 52 patients with ET without rest tremor, these 12 had disease of longer duration and greater severity. Also, their ET was more widely disseminated, as evidenced by a larger proportion with head tremor. None had clinical signs of bradykinesia or rigidity. The 5 patients with rest tremor who underwent electrophysiologic study had electrophysiologic features consistent with parkinsonism (eg, slow spiral speed and increased decrement of spiral speed with radius).

CONCLUSIONS

In our sample, 1 in 5 patients with ET had rest tremor. The tremor was associated with disease that was more severe, more disseminated, and of longer duration. Some of these patients had electrophysiologic features consistent with parkinsonism. The basis for the rest tremor could be basal ganglia involvement, raising the possibility that the pathologic process responsible for ET may extend to these structures.

[Depression in Parkinson disease: own experience]

The aim of the study was to evaluate the frequency of depression in patients with Parkinson's disease. The authors recruited 85 patients with idiopathic Parkinson's disease, 42 males and 43 females aged 34-82 years (mean age 68.7). Age at onset ranged 24-79 (mean 60.9 years). Disease duration ranged from 3 month to 20 years (mean 7.86 years). In 62 patients (72.94%) mixed type of the disease was diagnosed, in 14 (16.47%) tremor and in 9 (10.59%) rigidity predominated. UPDRS was used to evaluate the severity of the disease (results ranged 28-90, mean 51.4). Activity of daily living was estimated according to Schwab and England Scale (range 40-90, mean 68.1). Depression was evaluated with Hamilton, Beck and Montgomery-Asberg scales. The results were analysed with Spearman correlation. Depression was diagnosed in 53 (62.35%) patients [in 7 (8.24%) light; in 14 (16.47%) middle; in 19 (22.35%) heavy; in 13 (15.29%) very heavy]. The results acquired with all three scales were not statistically different. There were significant positive correlations between depression and female sex, severity of the disease, dyskinesia as side effect of.

Clinical features and comorbidity of mood fluctuations in Parkinson's disease

Parkinson's disease (PD) patients commonly develop fluctuations in their motor responses to levodopa within several years of initiation of treatment; some also develop nonmotor fluctuations. The authors performed a case-control study comparing the frequency of comorbid symptoms in 70 PD patients who experienced clinically apparent mood changes during their motor "on" or "off" states with two control groups with no mood fluctuations. Mood fluctuators had significantly younger age at onset and longer disease duration and were significantly more likely to have dementia, psychosis, clinical depression, and motor complications. This association remained after removing effects of age and disease duration.

HIV-related movement disorders: epidemiology, pathogenesis and management

Clinically relevant movement disorders are identified in 3% of patients with HIV infection seen at tertiary referral centres. In the same setting, prospective follow-up shows that 50% of patients with AIDS develop tremor, parkinsonism or other extrapyramidal features. Hemiballism-hemichorea and tremor are the most common hyperkinesias seen in patients who are HIV positive, but other movement disorders diagnosed in these patients include dystonia, chorea, myoclonus, tics, paroxysmal dyskinesias and parkinsonism. Patients with movement disorders usually present with other clinical features such as peripheral neuropathy, seizures, myelopathy and dementia. In the vast majority of patients, hyperkinesias result from lesions caused by opportunistic infections, particularly toxoplasmosis, which damage the basal ganglia connections. On the other hand, parkinsonism and tremor can result from dopaminergic dysfunction resulting from HIV itself or the use of antidopaminergic drugs. The management of patients who are HIV positive who present with movement disorders involves recognition and treatment of opportunistic infections, symptomatic treatment of the movement disorder and the use of highly active antiretroviral therapy (HAART). The most effective treatment of cerebral toxoplasmosis in patients with HIV infection is the combination of sulfadiazine and pyrimethamine. Symptomatic treatment of the movement disorder is often disappointing: hemiballism improves with antipsychotics, but tremor, parkinsonism and other phenomena usually fail to respond to available therapies. Preliminary data suggest that HAART may be helpful in the symptomatic control as well as prevention of movement disorders in patients who are HIV positive.

Rhythmic feet movements while falling asleep

During the wake-sleep transition and sleep, diverse motor phenomena such as hypnagogic foot tremor may occur in the lower extremities. We investigated the relevance of this phenomenon in 375 consecutive subjects examined polysomnographically in a sleep disorders center. Rhythmic feet movements while falling asleep (RFM) were found in 28 subjects (7.5%). RFM occurred mostly as single, short series with a duration of between 10 and 15 seconds. They had a high night-to-night variability and were detected as rhythmic, oscillating movements of the whole foot or toes. Surface electromyographic (EMG) recordings displayed series of repetitive phasic bursts with a periodicity mostly between 1 and 2 per second. Single EMG burst duration varied between 300 and 700 msec. RFM at highest intensity occurred during presleep wakefulness, and usually persisted in sleep stages 1 and 2. RFM did not have a major sleep-disturbing effect in any of the affected subjects. Due to its high prevalence and the lack of a major sleep-disturbing effect, short series of RFM could be considered a quasiphysiological phenomenon. However, in more severe forms of RFM with evidence of a sleep-disturbing effect, RFM should be considered abnormal.

Risk of tremor and impairment from tremor in relatives of patients with essential tremor: a community-based family study

Essential tremor (ET) is a common condition that is present in as many as 23% of elderly individuals. Our objective was to determine the risk of ET and to study the impairment resulting from ET among relatives of ET cases compared to relatives of controls. ET cases and matched controls from the Washington Heights-Inwood community, New York, and their first- and second-degree relatives underwent a standardized tremor examination. The risk of having ET in relatives of cases vs relatives of controls was compared using Cox proportional hazards models. Five hundred ninety-one subjects were examined (59 ET cases, 72 controls, 234 case relatives, and 226 control relatives). ET was present in 25 (22.5%) of the 111 first-degree relatives of cases compared to 6 (5.6%) of 107 first-degree relatives of controls [relative risk (RR) = 4.67, 95% confidence interval (CI) = 1.90-11.49, p = 0.0008]. RRs were higher in relatives of cases with onset < or =50 years than in those with later onset (RR = 10.38 vs 4.82). Sixteen (64%) of twenty-five affected first-degree case relatives exhibited moderate tremor while performing tasks such as writing, drinking, or pouring. Relatives of ET patients are five times more likely to develop the disease than are members of the population and ten times more likely if the proband's tremor began at an early age. The majority of the affected relatives can expect to experience impairment resulting from tremor.

Neurological complications in the European multicentre study of FK 506 and cyclosporin in primary liver transplantation

Neurological complications were examined in a multicentre, randomized, parallel-group study of 545 patients undergoing primary liver transplantation to compare the efficacy and safety of FK 506- and cyclosporin A-based immunosuppressive regimens (CBIR). In an additional analysis, patients were divided into early and late randomized cohorts to detect the influence of protocol amendements that allowed for FK 506 dose reductions. Initial follow-up was for 6 months. Tremor, headache and insomnia were the most frequently reported adverse events involving the neurological system. Whereas these neurological symptoms were observed significantly more often in FK 506-treated patients (P < 0.05 vs. CsA for the overall population), this was no longer the case for the late FK 506 and CBIR cohorts. The risk of FK 506-treated patients developing tremor was related to the initial i.v. dose, the rate of administration of the i.v. dose and the daily dose (P < 0.01). Headache was significantly correlated with the FK 506 dose (P < 0.05), and insomnia was not related to any dosing variable. Major neurological symptoms, including psychosis, convulsion, coma, aphasia and intracranial haemorrhage, were reported with a low frequency (0.4-5.2%), and differences between both treatment groups were neither significant for the overall population nor for the early and late cohorts of FK 506 and CBIR. Data from the late cohorts showed no differences in the overall incidence of neurological adverse events between FK 506- and CBIR-treated patients.

Agreement between clinical examination and quantitative tests of neurologic function among 384 subjects

BACKGROUND

Quantitative neurological tests are often cheaper and easier than clinical examinations, and provide continuous data which may discriminate between exposed and nonexposed groups with more sensitivity than dichotomous (normal/abnormal) examination data.

METHODS

We compare clinical examinations and analogous quantitative tests for arm tremor, postural sway, and vibrotactile sensitivity (finger and toe), for 384 subjects.

RESULTS

The "abnormal" clinical outcomes studied were relatively common (range, 3-36%), and did not result in impairment of daily activity for affected subjects. All the quantitative tests were reasonably good predictors of the corresponding clinical outcome. The most predictive test was for toe vibrotactile sensitivity. The probability of an abnormal clinical result for those in the worst quartile for the toe test was 0.63, compared with 0.36 for all subjects.

CONCLUSIONS

Our results suggest that certain quantitative tests might be used in epidemiologic studies instead of a physical examination.

Relationships between quantitative measures and neurologist's clinical rating of tremor and standing steadiness in two epidemiological studies

OBJECTIVE

The purpose of the present investigation was to 1) compare a neurologist's physical examination (NPx) rating of severity of postural tremor to several summary measures derived from quantitative measurements of tremor and 2) compare a NPx rating of standing steadiness and related clinical findings to quantitative sway speed measurements.

METHODS

Comparisons were performed on data obtained from two epidemiological field studies: 1) retired heavy industrial workers (n= 198, approximately half previously exposed to elemental mercury), and 2) small town residents (n=234, approximately 40% with environmental exposure to arsenic). A commercially available tremor measurement instrument was used in both studies. To obtain standing steadiness measures, a head position monitoring device was used in the mercury study, and a force platform was used in the arsenic study. The NPx included assessment of postural tremor, as well as evaluation of vibration perception and proprioception of the great toe, Achilles tendon reflex activity, Romberg test status, and tandem gait. One neurologist performed all the NPx in both studies and results were graded as normal, equivocal, or abnormal. The square root of the proportion of variance accounted for by a linear trend term in ANOVA models was used as an estimate of association between quantitative tests and clinical examination grade. An estimate of agreement, kappa, was also calculated after both NPx and quantitative test results were dichotomized.

RESULTS

Most tremor summary measures varied monotonically with NPx tremor severity grade. Moderately good associations were observed between the tremor acceleration measure and NPx postural tremor grade (correlations up to approximately 0.5). Sway speed with eyes open and with eyes closed increased monotonically with NPx grade for most of the clinical signs. The NPx signs showing the strongest relationships with sway speed were Romberg test performance, tandem gait, and proprioception and vibration sensation of the great toe (correlations up to approximately 0.5).

CONCLUSIONS

Quantitative tremor measurements were related to a neurologist's grading of postural tremor. Sway speed was associated with several NPx findings related to standing stability. Quantitative measurements of tremor and standing stability may provide more precise and objective measures of neurological function than NPx by a neurologist and are likely to be more consistent across times and examiners.